It is known to provide a gaming system which comprises a game controller arranged to randomly select and cause the display of several symbols from a predetermined set of symbols and to determine a game outcome, such as a game win, based on the displayed symbols. Such gaming systems may commonly be implemented as a stepper machine provided with reels with each reel carrying several symbols of the set, or a video machine wherein selected symbols are displayed on virtual reels on a graphical display device. Win outcomes can occur based on symbols appearing in one or more horizontal lines, diagonal lines, or any other predetermined way. Typically five reels across are provided on the display (although less or more may be provided). Each reel or virtual reel display is three symbols high in the display window for the reel (although, again, this may be more or less symbols high).
In many countries, the regulations prescribe that the number of available symbols to select from be a fixed number. With stepper reels this is implemented by having a fixed number of symbols on each reel. With video implementation or other “virtual” reel implementations this is implemented in a similar manner, by allowing only a predetermined number of symbols for each virtual reel. A problem with requiring a fixed number of reel “stops”, whether virtual or stepper, is that this limits the number of combinations that a typical reel game can provide for entertainment of the player.
In many gaming systems, a player can choose whether or not to wager on one or more win lines for each play of the game. The value of the wager for each win line may be determined by the player. A prize awarded to the player for a winning combination on a win line will generally be in proportion to the amount of credits bet for that win line by the player. This is perceived to be fair, as the more credits that the player is willing to risk, the higher the potential return.
While it is a simple matter to scale the amount of prize return with regard to the amount of credit bet by the player for prizes that are of known value for a winning combination, it is not possible to do this for jackpot prizes, which accumulate over a period of time. Jackpot prizes may, for example, depend on a percentage amount of credits entered into a gaming machine over a period of time, or even a percentage amount of credits entered into linked gaming machines (linked jackpots) over a period of time. Winning of the jackpot is generally independent of the amount of credit wagered on any particular win line by a player. This is perceived as being unfair to players who are willing to wager large amounts of credit in order to win a jackpot.